The present invention relates to a writing utensil for a free-flowing writing fluid. The text which now follows refers to a writing utensil which is also suited for use in drawing, depicting, and marking things. In particular, writing utensils in the sense of the application also comprise markers, highlighters, felt tip pens and the like.
From GB 2 310 592, the entire contents of which is incorporated herein by reference, a marker is known which has a valve for the control of liquid passage into a supply duct from a reservoir. The supply duct extends up to a marker tip through a feeding element. The feeding element is of a retractable configuration in order to open the valve when the marker tip is urged against a surface. An auxiliary chamber is provided between the valve member, which is formed as a sphere, and the feeding element. The forechamber is sealingly closed by an elastic membrane in such a way that if the pressure on the writing tip lessens the membrane returns to its initial position while pulling the valve member back into the valve seat.
DE 40 15 586 C3, the entire contents of which is incorporated herein by reference, has made known an utensil for applying a fluid for writing, depicting, printing or drawing things or the like, which has a liquid container, a writing tip, and an air, supply tube which connects the container interior to the outer atmosphere. In addition, a capillary liquid tank is provided which is formed as a fluid-conveying device. In the known utensil, the fluid-conveying device completely extends through the interior of the tank. The air supply tube additionally is filled with a capillary material to prevent liquid from leaking via the tube.
From U.S. Pat. No. 6,575,650 B1, the entire contents of which is incorporated herein by reference, a pencil is known in which the ink is discharged through a valve. A writing tip is disposed to be longitudinally displaceable in the front portion of the pencil. While writing is done the writing tip is pushed back and the valve opens so that ink may be fed to the writing tip. At the same time, the ink inflow to the valve is blocked by a head of the retracted writing tip so that merely a predetermined amount of ink is supplied to the writing tip. If this amount of ink is used up the pencil needs to be lifted off in order that the valve be closed again and fresh ink may flow to the valve again.
WO 93/05966, the entire contents of which is incorporated herein by reference, has made known a writing utensil the reservoir of which connects to the surroundings via a through bore. The writing fluid is sealed from the through bore by means of a movable plug.
It is the object of the present invention to provide a leak-proof writing utensil which, by using simple means, creates a continuous flow of writing fluid.